Cellulosic composition



. EDENEZER EMMET REID, or BALTIMORE, MARYLAND, AND GEoRGE L. 'scEwAR'rz, oE

WILMINGTON, ELAWARE, AssIeno s TO E. or wrnmmeron, A coRro A'rIoN or DELAWARE No Drawing.

' and soluble cellulose compounds,

Patented 14, 1930 UNITED STATES PATENT OFFICE I. DU

GELLULOSIC COMPOSITION This invention relates to cellulosic compositions containing as an essential constituent a cyclohexyl phthalate, and has more particular reference to cellulose nitrate compositions, for example, coatings and plastics, containing cyclohexylbutyl 'hthalate.

In the practical use 0 dissolved cellulose including cellulose esters, in the arts, as in making films, coatings for artificial leather, plastics and so 'on, it is customary to add to the cellulose ester, or its solution, certain noni-cellulosic materials commonly termed softeners,'ca1nphor substitutes or the like, such additions being made for the mability, flexibility and so forth. For convenience, We shall herein term these materials the following general graphical formula modifiers. The modifiers discussed herein as particularly related to the invention serve primarily as softeners and camphor substitutes in the manufacture vof cellulose nitrate coatings and plastics. We have found that cyclohexyl phthalates, including broadly. esters of phthalic the two carboxyl groups is substituted by a cyclohexyl groupyaredesirable modifiers for cellulosic compositions, certain of their advantages being their very low volatility at room temperature,) very excellent solvent 7 other cyclohexyl alkyl phthalates, and on the other hand as cyclohexyl phenyl phthalate, cyclohexyl xylyl phthalate, and other cyclohexyl aryl phthalates, all of which ester's'have in which R stands for the cyclohexyl group and R represents a hydrogen, alkyl, or aryl "'5 radical.

We may say, however, that we have found purpose of imparting some desired properties, such as,non-1nflam-.

acid in which the hydrogen radical of at least one of Application filed May 16, 1925. Serial No. 30,872.

certain of the esters more suitable, due say to certain physical characteristics, than others. Thus, cyclohexyl butyl phthalate is partigu larly desirable, while on the other hand the. neutral (or di-) cyclohexyl phthalate is, generally speaking, somewhat diflicult of application because of its highviscosity. Which ester will be most suitable under s ecified conditions will depend somewhat upon ease of application and like factors under the particular circumstances existing, as will be evident to those skilled in the art of using modibodying the invention the esters may be used PON'I' DE NEMOURS &' COMPANY,

'fiers and preparing cellulosic compositions in varlousproportions depending upon the particular resultssought. For example, for

pyroxylin-( 12% nitrogen) artificial leather coatings containing the usual amount of pigment' the esters, particularly cyclohexyl butyl phthalate, can be used in the ratio of ester 0.60pyroxylin 1.00,to-ester 1.40pyroxylin- 1.00. In clearpyroxylin-coatin s the ester ratio is .corresponding reduce 'In pyroxylin plastics the esters may be used as camphor substitutes in the ratio of camphor that is regularly employed for such plastics and\may be-use'd similarly in the preparation of pyroxylin, pyroxy-lin lacquers, and pyroxylin for split leather coatings. Furthermore, i-ncompositions wherein castor oil is generally used as a softener, the composition may be made up with the esters as substitutes for the castor oil, to improve pliability.

pressure considerably lower than that of di- -butyl phthalate or camphor, the composition combinedas softeners with other soluble cel- Again, where a composition is re-. qun'ed having a solvent softener'wlth a vapor lulose compounds, for example, wemay use cellulose acetate combined with hexyl butyl phthalate.

While the present invention is not primarily concerned with the preparation of modifiers of the type indicated, the method of. making mixed esters may be illustrated by I the following example relating to the 'prgs duction of cyclohexyl normal-butyl phthalate One molecular portion (if cyclohexanol" (boiling point 158 1'Z'al C.-95% distilling at 161 0.), and onemolecular portion of phthalic anhydride are heated together several hours at 150C. until analysis shows that practically all of the alcohol has been esterified. -Normal butyl alcohol (about two molecular portions) 'is then added to the mixture and heated at a refluxing temperature under atmospheric pressure. The condenser.

denser is changed to a distilling position and the temperature is raised gradually to 2110"- -C. In the last stages of heating a stream of esteir and a mixed cyclohexyl ester of phthalic aci 2. A composition containing a cellulose ester and a cyclohexyl ester of phthalic acid having the following graphical formula:

coo-n :C0.0-R' wherein R stands for the cyclohexyl group, and R represents .an alkyl radical.

3. A composition containing cellulose nitrate and-cyclohexylbutyl phthalate.

In testimony-whereof we aflix our signatures.

EBENEZER EMMET REID.

GEORGE L. SCHWARTZ.

nitrogenis passed through themixtu're to remove the last traces of butyl alcohol. Only a small amount of cyclohexanol is lost. The

. ratio of cyclohexanol to butyl alcohol that reacts can be approximately regulated so that any mixture of esters can be obtainedgrading from ure dibutyl phthalate through cyclohexyl utyl phthalate to dicyclohexyl phthalate, including mixtures of all of the pure and mixed esters that are ossible from the two alcohols and the anhy ride. T

Cyclohexyl butyl phthalate, containing cyclohexanol and butyl alcohol radicalsin apcosity sufiiciently' low'to render it readily proximately equal ratio, is a, transparent liquid at ordinary temperatures,'witli a visand easily usable as a modifier. It colloids dry nitrocellulose readily at 21 C. and rapidlyat 0. Although, as has been in,-

h dicated, cyclohexyl butyl phthalate is asso- I can be disregarded so far as the use Of thQTGyclohexyl butyl phthalate itself as a softener ciated, when prepared according to the process given, with certain amounts of di utyl phthalate and-dicyclohexyl phthalate, these is concerned.

While particular-reference has been made above to pyroxylin compositions, it will be understood that the invention is not confined thereto, since other cellulosic compositions, as those of cellulose acetate, are within the purview of the invention so far as the said modifiers find beneficial use therein.

Cyclohexyl phthalatesare claimed, and

their preparation described, in Patent 1,643, 393, granted September 27, 1927, on our 00-' pending application, Serial No. 57 5.311, filed July '15, 1922.

By the term alkyl as used herein we mean a radical of an aliphatic hydrocarbon.

-We claim:

1 A composition containing a cellulose 

